The U.S. contribution to

Climate Variability and Predictability

VAMOS Ocean-Cloud-Atmosphere-Land Study

Overall science objectives: To develop and promote scientific activities leading to improved understanding, model simulations, and predictions of the southeastern Pacific (SEP) coupled ocean-atmosphere-land system, on diurnal to interannual timescales. Our two leading concerns are (1) the physical processes affecting the radiative and microphysical characteristics of the persistent stratocumulus clouds of this region, and (2) the ocean budgets of heat and other constituents, and how they determine the sea-surface temperature (SST) throughout this region. The most recent documents on the VOCALS program are below:

• Scientific Program Overview (pdf)
• Experimental Design Overview (pdf)
• VOCALS Modeling Plan (pdf)

Science and Implementation plans and additional documents can be found at: www.joss.ucar.edu/vocals

• The WHOI stratus buoy at 20S, 85W, which is providing continuous surface and subsurface meteorological and flux measurements and a profile of subsurface measurements since October 2000,
  
• Extensive surface-based remote sensing, surface meteorology and fluxes, and limited aerosol sampling by NOAA-ETL from annual maintenance cruises to the WHOI buoy in austral spring
  
• Automated surface meteorological measurements from San Felix Island (27S 80W) since December 2002.

• comprehensive observational comparisons of modelled SEP clouds, SST, and surface heat budget with SEP observations;

• improvement of forecasts on daily, seasonal-interannual, and climate timescales by improvement of parameterizations important for cloud-topped boundary layers, including modeling of the aerosol indirect effect on climate, and ocean mixing/upwelling processes;

• sensitivity studies of ENSO, seasonal cycles and mean biases to cool-ocean physical processes and the coupling to the neighboring South American continent;

• regional ocean modeling of the SEP upwelling region to understand the small-scale dynamics, SST variability, and heat/salt/nutrient transport processes, given additional funding.

Expected Outcomes